The premise sounded great, even if it was not the most original of ones (it's not got the unique structure of "The Saddle Row Review" for example). Love Rarity as a character, and Seasons 4 and 5 did on the most part so well with her in terms of character writing (despite there being episodes where she was better than the episodes overall themselves). Pinkie Pie is more hit and miss for me but when she is written well she is great. Anybody interested in seeing the two together are likely to find themselves quite excited.
"Spice Up Your Life" was not a bad episode at all, on the most part it was quite good actually in my view. It was great seeing Rarity and Pinkie Pie together and the story entertains and heart-warms. So there is enough flavour to the mix. Yet "Spice Up Your Life" could have done with more spice, which there would have been more of if some of the characterisation appealed more and if the episode hadn't tried too hard on one major aspect of the plot.
Fortunately, there is more good than bad in "Spice Up Your Life". The animation is as colourful and eye-catching as ever, the character animation getting more polished and elaborate with each season. The music fits the action very well and has character and emotion. "It's Gonna Work" is a catchy and heart-warming song and hearing Shannon Chan-Kent and Kazumi Evans blend so wonderfully was a pleasure. The voice acting from Andrea Libman and Tabitha St Germain has a lot of gusto and nuance, Libman particularly.
Much of the writing is beautifully balanced, it's funny and smart as well as warm and sweet. The moral is a great one that has always been important to teach and still is (it is an episode to see for anybody who thinks that critic bashing on a regular basis is okay), it's delivered with force yet tact. Much more subtly than the handling of the Cutie Map task. The story is heart-warming, with a very sincerely written father and daughter (both relatable characters) relationship. Pinkie Pie is very funny here as well as well meaning and she and Rarity play off each other so entertaining.
Was not as completely sold on Rarity, she meant well but she did come over as a bit rude and stubborn at times. Which is sad for anybody that loved how she was written in Seasons 4 and 5, like me. The worst character was Zesty Gourmand, really do not like anybody that passes a negative judgement on anything without giving it a chance (either properly or any, feel the same about anybody that passes judgement on somebody without knowing the full story).
Did feel that the Cutie Map task aspect could have been handled better, the whole one character being right and the other being wrong aspect that dominated it was too obvious and heavy-handed for my tastes.
Concluding, quite good. 7/10